Precision Viticulture :The future of our vineyards
Most winemakers suppose Precision Viticulture (PV) is a new trend. Well, that is partially true, at least for Europe. If we could compare the age of PV with the age of a man, PV would be able to vote by now.
Precision Agriculture (PA) took its first baby steps back at the early 80’s with the research of the University of Minnesota (varied lime inputs in crop fields) along with the practice of grid sampling. At that time lack of technology made PA unpractical and expensive for commercial use. It was not until the development of the GPS that we can assume that PA reaches its adulthood. With the advancement of the new technology variable-rate spreading techniques were feasible which helped to anchor precision farming among the leading agricultural countries (USA, Canada, and Australia).
Australian viticulturists, along with USA and Canada, eagerly adopted the new technology and integrate a more scientific approach into their already advanced cultivation techniques. The obvious benefits in wine quality and production cost spread the new way of viticulture across the 3 major winemaking continents (America, Australia, Europe), although Europe was the last to embrace it mainly due to the stronger bonds to traditional wine-making methods.
In order to better understand why PV offers such a major shift in viticulture and winemaking, we have to understand what Precision Viticulture stands for. Let’s see…
The word “Precision” is used because PV heavily depends on separating the field in management zones based on various agronomic information and act on that precise area. Creating a management zone is based on three main variables: what farmers see, what can be measured (soil texture, nutrients, and organic matter), and what is achieved in terms of high, average, or low crop yields. All this information is then taken together and mapped out to produce a management zone. Till recently creating a map from measured data was an expensive and time-consuming task. You had to buy a sensor and move it all around your field in order to gather all the data that are necessary to create the grid. The advance of multispectral photography made it possible to gather all these data with just a simple shot. Nowadays multispectral images from satellites or Unmanned Aerial Vehicles (UAV) can be processed to valuable data arrays of variable indexes of our field.
An interesting example of an index from multispectral imaging is the Normalized Difference Vegetation Index (NDVI) which is a simple metric that indicates the health of vegetation. Studying wavelengths above visible red (Near Infrared, NIR) we have observed that chlorophyll reflects a
high amount of NIR radiation when healthy. The healthier the plant, the more chlorophyll it has, the more NIR reflected back to the atmosphere. If we combine the reflectance of the NIR radiation with the radiation of the visible colors we can find not only if there is plant material but also the health of it.
From a single high definition image, taken from 10m above the ground, we can have an index for every 3mm of our field or separate a single grape to 3 different indexes.
Another great example of multispectral imaging is with InfraRed or thermal radiation. Using specialized cameras we can capture the wavelengths that are emitted by heated objects. Areas with high moisture in the soil are cooler than areas with lower moisture levels so with a thermal camera we can easily distinguish between them. Using the thermal image we could create zones with different irrigation needs and employ specific irrigation strategies to overcome water stress.
There are numerous other indexes, using different radiation bands and algorithms, that can create zones on our field. The lack of uniformity among vines results in variability in grape quality and in the rate of ripening, which affects wine quality.
Last, but not least, PV can help in managing crop production inputs in an environmentally friendly way. By targeting rates of fertilizer, seed and chemicals for soil and other conditions using the site-specific knowledge we can reduce the environmental impact of viticulture, contributing to the sustainability of agricultural production.
In conclusion, Precision Viticulture enable us to manage the terroir more efficient than ever before without compromising future generations’ ability to taste the same quality wines.